TWI632451B - Solar energy display device - Google Patents

Abstract

A solar display device may include a solar cell layer, a liquid crystal layer, and a polarizing plate. The solar cell layer may include a transparent electrode, a photovoltaic layer, and a metal reflective layer; the transparent electrode may be disposed above the photovoltaic layer and may be used as a first electrode; the metal reflective layer may be disposed below the photovoltaic layer and may be used as a second electrode Electrode; the photovoltaic layer can be used to convert light energy into electrical energy, so that a potential difference can be generated between the transparent electrode and the metal reflective layer. The liquid crystal layer may be disposed on the solar cell layer. The polarizing plate may be disposed on the liquid crystal layer.

Description

   Solar display device   

The invention relates to a display device, in particular to a solar display device.

Due to the advancement of science and technology, a variety of electronic devices with different functions have been developed to meet different needs of people; and in order to increase the portability of electronic devices, many different wearable devices have also been developed in recent years, such as smart Watches, smart glasses, smart clothes, etc., and these devices need to display various information through the liquid crystal display device to interact with the user to provide multiple functions.

Please refer to FIG. 1A and FIG. 1B, which are a first schematic diagram and a second schematic diagram of the display device 1 of the conventional art. As shown, the display device 1 may include a polarizing plate 11, a liquid crystal layer 12, and a reflective layer 13.

The polarizing plate 11 is disposed above the liquid crystal layer 12, and the liquid crystal layer 12 is disposed above the reflective layer 13. When the incident light L penetrates the polarizing plate 11, the polarizing plate 11 allows light having a polarization direction parallel to its transmission axis to pass to generate polarized light PL, and the liquid crystal layer 12 can change the arrangement of liquid crystal molecules to determine the polarization direction of the polarized light PL The reflective layer 13 can reflect the polarized light PL to the liquid crystal layer 13; directions D and D ′ in the figure represent the polarization directions of the polarized light PL.

As shown in FIG. 1A, when the display device 1 is turned off, the incident light L penetrates the polarizing plate 11 to generate polarized light PL, and when the polarized light PL penetrates the liquid crystal layer 12, the arrangement of the liquid crystal molecules of the liquid crystal layer 12 can be polarized The polarization direction of the light PL is changed from D to D 'so that it is perpendicular to the transmission axis of the polarizing plate 11. Therefore, after the polarized light PL is reflected by the reflective layer 13 and penetrates the crystal layer 12 again, the polarized light PL cannot penetrate the polarizing plate. 11. At this time, the display device 1 may be in an opaque state.

As shown in FIG. 1B, when the display device 1 is turned on, the incident light L penetrates the polarizing plate 11 to generate polarized light PL, and when the polarized light PL penetrates the liquid crystal layer 12, the liquid crystal layer 12 can change the arrangement of its liquid crystal molecules. The polarization direction D of the polarized light PL and the transmission axis of the polarizing plate 11 are kept parallel. Therefore, after the polarized light PL is reflected by the reflective layer 13 and penetrates the liquid crystal layer 12 again, the polarized light PL can penetrate the polarizing plate 11 to make the display device 1 may be in a light-transmitting state.

However, the polarized light PL includes not only visible light components, but also invisible light components, and these invisible light components are not related to the display function of the display device 1. However, the display device 1 does not include any mechanism to make full use of these invisible light components. Of energy and therefore a waste of energy.

In addition, some electronic devices, such as wearable devices, have lower power consumption, but still need to be powered by batteries, which increases their cost.

In addition, since the power of the battery of the wearable device is limited, the user also needs to frequently remove the wearable device and charge the battery of the wearable device, which is extremely inconvenient to use.

Therefore, how to propose a display device that can effectively improve the display device of the conventional art with low energy utilization efficiency, high cost, and inconvenience has become an urgent issue.

In view of the problems of the above-mentioned conventional techniques, one of the objects of the present invention is to provide a solar display device to solve the problems of low energy efficiency, high cost, and inconvenient use of the conventional display devices.

According to one object of the present invention, a solar display device is provided, which may include a solar cell layer, a liquid crystal layer, and a polarizing plate. The solar cell layer may include a transparent electrode, a photovoltaic layer, and a metal reflective layer; the transparent electrode may be disposed above the photovoltaic layer and may be used as a first electrode; the metal reflective layer may be disposed below the photovoltaic layer and may be used as a second electrode Electrodes; the photovoltaic layer can be used to convert light energy into electrical energy, and can cause a potential difference between the transparent electrode and the metal reflective layer. The liquid crystal layer may be disposed on the solar cell layer. The polarizing plate may be disposed on the liquid crystal layer.

According to one object of the present invention, a solar display device is further provided, which may include a solar cell layer, a reflective layer, a liquid crystal layer, and a polarizing plate. The solar cell layer may include a transparent electrode, a photovoltaic layer, and a metal electrode; the transparent electrode may be disposed above the photovoltaic layer; the metal electrode may be disposed below the photovoltaic layer; the photovoltaic layer may be used to convert light energy into electrical energy, and may enable the transparent electrode A potential difference occurs with the metal electrode. The reflective layer may be disposed on the solar cell layer. The liquid crystal layer may be disposed on the reflective layer. The polarizing plate may be disposed on the liquid crystal layer.

As mentioned above, the solar display device according to the present invention may have one or more of the following advantages:

(1) In one embodiment of the present invention, the solar cell layer of a solar display device can absorb invisible light components in polarized light and convert them into electrical energy, and reflect visible light components in polarized light, so these can be used more fully No visible light energy, so it has better energy efficiency.

(2) In one embodiment of the present invention, the solar cell layer of the solar display device can absorb invisible light components in polarized light and convert it into electrical energy to provide power to the solar display device. Therefore, an electronic device with lower energy consumption does not It also needs to be powered by a battery to operate normally, thus reducing costs.

(3) In one embodiment of the present invention, the solar cell layer of the solar display device can absorb invisible light components in polarized light and then convert it into electrical energy to continuously charge the battery of the electronic device, so the user does not need to frequently perform the electronic device Charging makes it easier to use.

(4) In one embodiment of the present invention, even in a state where the solar display device is turned off, the solar cell layer of the solar display device can still provide power continuously, so the purpose of energy saving and power saving can be achieved.

1‧‧‧ Display device for learning skills

11‧‧‧ polarizing plate

12‧‧‧ LCD layer

13‧‧‧Reflective layer

2‧‧‧Solar display device

21‧‧‧Polarizer

22‧‧‧LCD layer

23‧‧‧ solar cell layer

231‧‧‧Transparent electrode

232‧‧‧Photovoltaic layer

233‧‧‧metal reflective layer

234‧‧‧metal electrode

24‧‧‧Reflective layer

D, D’ ‧‧‧ polarization direction

L‧‧‧ incident light

PL‧‧‧polarized light

V‧‧‧Output voltage

FIG. 1A is a first schematic diagram of a display device of a conventional technique.

FIG. 1B is a second schematic diagram of a display device of a conventional technique.

FIG. 2 is a first schematic diagram of a first embodiment of a solar display device according to the present invention.

FIG. 3 is a second schematic diagram of the first embodiment of the solar display device of the present invention.

FIG. 4 is a third schematic diagram of the first embodiment of the solar display device of the present invention.

FIG. 5 is a first schematic diagram of a second embodiment of a solar display device according to the present invention.

FIG. 6 is a second schematic diagram of the second embodiment of the solar display device of the present invention.

FIG. 7 is a third schematic diagram of the second embodiment of the solar display device of the present invention.

Hereinafter, embodiments of the solar display device according to the present invention will be described with reference to related drawings. For clarity and convenience of illustration, the components in the drawings may be exaggerated or reduced in size and proportion. In the following description and / or patent application, when an element is referred to as being "connected" or "coupled" to another element, it can be directly connected or coupled to the other element or intervening elements may be present; and when an element is referred to When "directly connected" or "directly coupled" to another element, there is no intervening element; similarly, when an element is referred to as being "on" another element, it can be directly disposed on the other element Intervening elements may exist on it; and when an element is referred to as being "directly on" another element, there are no intervening elements; other words used to describe the relationship between elements or layers should be the same Way to explain. In order to facilitate understanding, the same elements in the following embodiments are described with the same symbols.

Please refer to FIG. 2, which is a first schematic diagram of a first embodiment of a solar display device of the present invention. As shown, the solar display device 2 may include a solar cell layer 23, a liquid crystal layer 22, and a polarizing plate 21.

The solar cell layer 23 may include a transparent electrode 231, a photovoltaic layer 232, and a metal reflective layer 233.

The transparent electrode 231 may be disposed on the photovoltaic layer 232 and may be used as a first electrode, which is a positive electrode in this embodiment; in a preferred embodiment, the transparent electrode 231 may be an indium tin oxide (ITO) electrode or the like.

The metal reflective layer 233 may be disposed under the photovoltaic layer 232 and may be used as a second electrode, which is a negative electrode in this embodiment; in a preferred embodiment, the metal reflective layer 233 may be an aluminum metal layer or an aluminum alloy layer, etc. .

The photovoltaic layer 232 can be disposed between the transparent electrode 231 and the metal reflective layer 233, and can be used to convert light energy into electrical energy, so that a potential difference can be generated between the transparent electrode 231 and the metal reflective layer 233. The photovoltaic layer 232 can be transparent to visible light; in other words, it can absorb invisible light but allow visible light to pass through. The wavelength range of visible light is about 390nm ~ 780nm or 312nm ~ 1050nm, and the wavelength range of invisible light is less than 390nm. And above 780nm or below 312nm and above 1050nm. In a preferred embodiment, the photovoltaic layer 232 may be a single crystal silicon layer, a polycrystalline silicon layer, an amorphous silicon layer, a gallium arsenide (GaAs) layer, an aluminum gallium arsenide (GaAlAs) layer, an indium phosphide (InP) layer, A cadmium sulfide (CdS) layer or a cadmium telluride (CdTe) layer and the like.

The liquid crystal layer 22 may be disposed on the solar cell layer 23.

The polarizing plate 21 may be disposed on the liquid crystal layer 22.

Of course, the above content is only an example and is not intended to limit the present invention. The structure, connection relationship and function of each element of the solar display device 2 can be changed according to actual needs, and the present invention is not limited thereto.

Please refer to FIG. 3, which is a second schematic diagram of the first embodiment of the solar display device of the present invention. As shown in the figure, when the solar display device 2 is turned on, the incident light L penetrates the polarizing plate 21 to generate polarized light PL (directions D and D 'in the figure indicate the polarization directions of the polarized light PL). Then, the polarized light PL penetrates the liquid crystal layer 22 and the transparent electrode 231 and enters the photovoltaic layer 232. The photovoltaic layer 232 converts the energy of the invisible light component in the polarized light PL into electrical energy, which causes a potential difference between the transparent electrode 231 and the metal reflective layer 233. To output voltage V. At the same time, the metal reflective layer 233 reflects the polarized light PL so that the polarized light PL passes through the liquid crystal layer 22 and the polarizing plate 21 again, so that the solar display device 2 can be in a light transmitting state.

Of course, the above content is only an example and is not intended to limit the present invention. The structure, connection relationship and function of each element of the solar display device 2 can be changed according to actual needs, and the present invention is not limited thereto.

Please refer to FIG. 4, which is a third schematic diagram of the first embodiment of the solar display device of the present invention. As shown in the figure, when the solar display device 2 is turned off, the incident light L penetrates the polarizing plate 21 to generate polarized light PL. Then, the polarized light PL penetrates the liquid crystal layer 22 and the transparent electrode 231 and enters the photovoltaic layer 232. The photovoltaic layer 232 converts the energy of the invisible light component in the polarized light PL into electrical energy, which causes a potential difference between the transparent electrode 231 and the metal reflective layer 233. To output voltage V. At the same time, the metal reflective layer 233 reflects the polarized light PL so that the polarized light PL penetrates the liquid crystal layer 22 again. At this time, the arrangement of the liquid crystal molecules of the liquid crystal layer 22 can change the polarization direction of the polarized light PL from D to D ′, so that It is perpendicular to the transmission axis of the polarizing plate 21, so after the polarized light PL is reflected by the metal reflective layer 233 and penetrates the crystal layer 22 again, the polarized light PL cannot penetrate the polarizing plate 21, and the solar display device 2 may be opaque at this time status.

Of course, the above content is only an example and is not intended to limit the present invention. The structure, connection relationship and function of each element of the solar display device 2 can be changed according to actual needs, and the present invention is not limited thereto.

From the above, it can be known that the solar cell layer 23 of the solar display device 2 can absorb invisible light components in the polarized light PL and then convert them into electrical energy, and reflect the visible light components in the polarized light PL, so that these invisible light components can be used more fully Energy, it can effectively improve energy efficiency.

In addition, the solar cell layer 23 of the solar display device 2 can not only provide power when the solar display device 2 is turned on, but also provide power when the solar display device 2 is turned off. Therefore, the purpose of energy saving and power saving can be achieved.

It is worth mentioning that the display device of the prior art does not include any mechanism to make full use of the invisible light component in polarized light, thus causing a waste of energy. On the contrary, according to the embodiment of the present invention, the solar cell layer of the solar display device can absorb invisible light components in polarized light and convert them into electrical energy, and reflect visible light components in polarized light, so that these non-visible components can be used more fully. The energy of visible light components can effectively improve energy efficiency.

In addition, some electronic devices have lower energy consumption, but still need to be powered by batteries, which increases their cost. In contrast, according to an embodiment of the present invention, the solar cell layer of a solar display device can absorb invisible light components in polarized light and then convert it into electrical energy to provide power. Therefore, electronic devices with lower energy consumption do not need to be powered by batteries. It also works normally, thus reducing costs.

In addition, since the power of the battery of the electronic device is limited, the user also needs to frequently charge the battery of the electronic device, so it is extremely inconvenient to use. In contrast, according to the embodiment of the present invention, the solar cell layer of the solar display device can absorb invisible light components in polarized light and then convert it into electrical energy to continuously charge the battery of the electronic device, so the user does not need to frequently charge the electronic device. , So it's more convenient to use.

Furthermore, according to the embodiment of the present invention, even in a state where the solar display device is turned off, the solar cell layer of the solar display device can still provide power continuously, so the purpose of energy saving and power saving can be achieved. As can be seen from the above, the present invention has progressive patent requirements.

Please refer to FIG. 5, which is a first schematic diagram of a second embodiment of a solar display device according to the present invention. As shown, the solar display device 2 may include a solar cell layer 23, a reflective layer 24, a liquid crystal layer 22, and a polarizing plate 21.

The solar cell layer 23 may include a transparent electrode 231, a photovoltaic layer 232, and a metal electrode 234.

The transparent electrode 231 may be disposed on the photovoltaic layer 232 and may serve as a first electrode.

The metal electrode 234 may be disposed under the photovoltaic layer 232 and may serve as a second electrode.

The photovoltaic layer 232 can be disposed between the transparent electrode 231 and the metal electrode 234, and can be used to convert light energy into electrical energy, so that a potential difference can be generated between the transparent electrode 231 and the metal electrode 234. In this embodiment, the photovoltaic layer 232 can be transparent to visible light, but can absorb invisible light. In a preferred embodiment, the wavelength range of the invisible light that the photovoltaic layer 232 can absorb is less than 390 nm and higher than 780nm or below 312nm and above 1050nm.

The reflective layer 24 can be disposed on the solar cell layer 23. In a preferred embodiment, the reflective layer 24 can be made of a reflective material, and can reflect visible light with a wavelength range of about 390 nm to 780 nm or 312 nm to 1050 nm. Invisible light with wavelengths below 390nm and wavelengths above 780nm or below 312nm and above 1050nm is allowed to penetrate.

The liquid crystal layer 22 may be disposed on the reflective layer 24.

The polarizing plate 21 may be disposed on the liquid crystal layer 22.

Of course, the above content is only an example and is not intended to limit the present invention. The structure, connection relationship and function of each element of the solar display device 2 can be changed according to actual needs, and the present invention is not limited thereto.

Please refer to FIG. 6, which is a second schematic diagram of the second embodiment of the solar display device of the present invention. As shown in the figure, when the solar display device 2 is turned on, the incident light L penetrates the polarizing plate 21 to generate polarized light PL (directions D and D 'in the figure indicate the polarization directions of the polarized light PL). Then, the polarized light PL penetrates the liquid crystal layer 22 to the reflective layer 24. At this time, the reflective layer 24 can reflect the visible light component in the polarized light PL, and the invisible light component in the polarized light PL can penetrate the reflective layer 24 and the transparent electrode. After 231, it enters the photovoltaic layer 232, and the photovoltaic layer 232 converts the energy of invisible light components in the polarized light PL into electrical energy so that a potential difference is generated between the transparent electrode 231 and the metal electrode 234 to output a voltage V. At the same time, the visible light component in the polarized light PL can pass through the liquid crystal layer 22 and the polarizing plate 21 again, so that the solar display device 2 can be in a light-transmitting state.

Of course, the above content is only an example and is not intended to limit the present invention. The structure, connection relationship and function of each element of the solar display device 2 can be changed according to actual needs, and the present invention is not limited thereto.

Please refer to FIG. 7, which is a third schematic diagram of the second embodiment of the solar display device of the present invention. As shown in the figure, when the solar display device 2 is turned off, the incident light L penetrates the polarizing plate 21 to generate polarized light PL. Then, the polarized light PL penetrates the liquid crystal layer 22 to the reflective layer 24. At this time, the reflective layer 24 can reflect the visible light component in the polarized light PL, and the invisible light component in the polarized light PL can penetrate the reflective layer 24 and the transparent electrode. After 231, it enters the photovoltaic layer 232, and the photovoltaic layer 232 converts the energy of invisible light components in the polarized light PL into electrical energy so that a potential difference is generated between the transparent electrode 231 and the metal electrode 234 to output a voltage V. At the same time, the visible light component in the polarized light PL can penetrate the liquid crystal layer 22 again. At this time, the arrangement of the liquid crystal molecules of the liquid crystal layer 22 can change the polarization direction of the polarized light PL from D to D ′, so that it and the polarizing plate 21 The transmission axis is perpendicular. Therefore, after the polarized light PL is reflected by the reflective layer 24 and penetrates the liquid crystal layer 22 again, the polarized light PL cannot penetrate the polarizing plate 21, and the display device 2 may be in an opaque state at this time.

It can be known from the foregoing that the difference between the solar display device 2 of this embodiment and the previous embodiment is that the solar display device 2 of this embodiment is provided with a reflective layer 24, so that the photovoltaic layer 232 of the solar cell layer 23 does not need to be made of light-transmissive The material is made to make the solar cell layer 23 more flexible in material selection.

Of course, the above content is only an example and is not intended to limit the present invention. The structure, connection relationship and function of each element of the solar display device 2 can be changed according to actual needs, and the present invention is not limited thereto.

Similarly, the solar cell layer 23 of the solar display device 2 of this embodiment can also absorb the invisible light component in the polarized light PL and convert it into electrical energy, and reflect the visible light component in the polarized light PL, so it can be used more fully. The energy of these invisible light components can effectively improve energy efficiency.

In addition, the solar cell layer 23 of the solar display device 2 in this embodiment can also provide power when the solar display device 2 is turned on, and can also provide power when the solar display device is turned off, so it can achieve more energy saving and power saving. the goal of.

In summary, in one embodiment of the present invention, the solar cell layer of the solar display device can absorb invisible light components in polarized light and convert them into electrical energy, and reflect visible light components in polarized light, so it can be more fully Utilizing the energy of these invisible light components has better energy utilization efficiency.

In addition, in an embodiment of the present invention, the solar cell layer of the solar display device can absorb invisible light components in polarized light and convert it into electrical energy to provide power to the solar display device. Therefore, an electronic device with lower energy consumption does not need It can also operate normally through battery power, thus reducing costs.

In addition, in one embodiment of the present invention, the solar cell layer of the solar display device can absorb invisible light components in polarized light and then convert it into electrical energy to continuously charge the battery of the electronic device, so the user does not need to frequently charge the electronic device. , So it's more convenient to use.

Furthermore, in one embodiment of the present invention, even in a state where the solar display device is turned off, the solar cell layer of the solar display device can still continuously provide power, so the purpose of energy saving and power saving can be achieved.

It can be seen that the present invention has indeed achieved the desired effect under the breakthrough of the previous technology, and it is not easy for those skilled in the art to think about, and its progressiveness and practicability obviously meet the requirements of patent application. I filed a patent application in accordance with the law, and kindly ask your office to approve this invention patent application in order to encourage creativity and to feel good.

The above description is exemplary only, and not restrictive. Any other equivalent modification or change without departing from the spirit and scope of the present invention should be included in the scope of the attached patent application.

Claims (19)

A solar display device includes: a solar cell layer including a transparent electrode, a photovoltaic layer, and a metal reflective layer; the transparent electrode is disposed on the photovoltaic layer and serves as a first electrode; the metal reflection The photovoltaic layer is disposed under the photovoltaic layer and serves as a second electrode; the photovoltaic layer is used to convert light energy into electrical energy, so that a potential difference is generated between the transparent electrode and the metal reflective layer; a liquid crystal layer is provided On the solar cell layer; and a polarizing plate is disposed on the liquid crystal layer. The solar display device according to item 1 of the scope of patent application, wherein when an incident light penetrates the polarizing plate to generate a polarized light, the polarized light penetrates the liquid crystal layer and the transparent electrode and enters the photovoltaic layer, The visible light component of the polarized light is transmitted through the liquid crystal layer by being reflected by the metal reflective layer. The solar display device according to item 1 of the patent application scope, wherein the transparent electrode is an indium tin oxide electrode. The solar display device according to item 1 of the patent application scope, wherein the metal reflective layer is an aluminum metal layer or an aluminum alloy layer. The solar display device according to item 1 of the patent application scope, wherein the photovoltaic layer is a single crystal silicon layer, a polycrystalline silicon layer, an amorphous silicon layer, a gallium arsenide layer, an aluminum gallium arsenide layer, a An indium phosphide layer, a cadmium sulfide layer, or a cadmium telluride layer. The solar display device according to item 1 of the scope of the patent application, wherein the photovoltaic layer is transparent to visible light and can absorb invisible light. The solar display device according to item 1 of the scope of the patent application, wherein the first electrode system is a positive electrode and the second electrode system is a negative electrode. The solar display device according to item 6 of the scope of the patent application, wherein the photovoltaic layer can allow visible light having a wavelength of 390 nm to 780 nm to penetrate, and can absorb invisible light having a wavelength below 390 nm and a wavelength above 780 nm. According to the solar display device described in item 6 of the patent application scope, wherein the photovoltaic layer can allow visible light having a wavelength of 312 nm to 1050 nm to penetrate, and can absorb invisible light having a wavelength lower than 312 nm and a wavelength higher than 1050 nm. A solar display device includes: a solar cell layer including a transparent electrode, a photovoltaic layer, and a metal electrode; the transparent electrode is disposed on the photovoltaic layer; the metal electrode is disposed under the photovoltaic layer; The photovoltaic layer is used to convert light energy into electrical energy, so that a potential difference is generated between the transparent electrode and the metal electrode; a reflective layer is disposed on the solar cell layer; a liquid crystal layer is disposed on the reflective layer And a polarizing plate, which is disposed on the liquid crystal layer. The solar display device according to item 10 of the application, wherein when an incident light penetrates the polarizing plate to generate a polarized light, after the polarized light penetrates the liquid crystal layer, the visible light component in the polarized light is detected by the The reflective layer reflects and penetrates the liquid crystal layer again, and invisible light components in the polarized light penetrate the reflective layer and the transparent electrode and enter the photovoltaic layer. The solar display device according to item 10 of the application, wherein the transparent electrode is an indium tin oxide electrode. The solar display device according to item 10 of the scope of patent application, wherein the reflective layer is made of a reflective material, the reflective layer can reflect visible light with a wavelength of 390nm to 780nm, and the allowable wavelength is lower than 390nm and the wavelength is higher than 780nm Invisible light penetrates. The solar display device according to item 10 of the scope of patent application, wherein the reflective layer is made of a reflective material, and the reflective layer can reflect visible light with a wavelength of 312nm to 1050nm, and the allowable wavelength is lower than 312nm and the wavelength is higher than 1050nm. Invisible light penetrates. The solar display device according to item 10 of the scope of patent application, wherein the photovoltaic layer is a single crystal silicon layer, a polycrystalline silicon layer, an amorphous silicon layer, a gallium arsenide layer, an aluminum gallium arsenide layer, a An indium phosphide layer, a cadmium sulfide layer, or a cadmium telluride layer. The solar display device according to item 10 of the scope of patent application, wherein the photovoltaic layer is opaque to visible light and can absorb invisible light. The solar display device according to item 10 of the application, wherein the transparent electrode is a positive electrode and the metal electrode is a negative electrode. The solar energy display device according to item 16 of the patent application scope, wherein the photovoltaic layer is capable of absorbing invisible light having a wavelength lower than 390 nm and a wavelength higher than 780 nm. The solar display device according to item 16 of the patent application scope, wherein the photovoltaic layer is capable of absorbing invisible light having a wavelength lower than 312 nm and a wavelength higher than 1050 nm.